Permutation arrays of period n.

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =4a(5) =10a(6) =28a(7) =127a(8) =686a(9) =4975a(10) =42529a(11) =420948a(12) =4622509a(13) =55670332a(14) =726738971a(15) =10217376792a(16) =153848448652